Preparation Steps

• Preheat oven to 350°F (175°C). Line an 8x8 inch baking pan with parchment paper, leaving an overhang on the sides.
• In a double boiler or microwave-safe bowl, melt butter and chopped semisweet chocolate together until smooth. Stir in 1 cup of granulated sugar.
• Whisk in 2 large eggs one at a time, then stir in 0.5 teaspoon vanilla extract.
• In a separate bowl, whisk together 0.5 cup all-purpose flour, 0.25 teaspoon salt, and 0.25 cup unsweetened cocoa powder.
• Gradually add the dry ingredients to the wet ingredients, mixing until just combined. Do not overmix.
• In a medium bowl, beat together 8 ounces softened cream cheese and 0.33 cup granulated sugar until smooth. Stir in 1 large egg yolk and 0.5 teaspoon vanilla extract.
• Spread half of the brownie batter into the prepared baking pan. Dollop spoonfuls of the cheesecake mixture over the brownie batter.
• Gently spread the remaining brownie batter over the cheesecake mixture, then swirl the two batters together with a knife or toothpick.
• Bake for 30-35 minutes, or until a toothpick inserted into the center comes out with moist crumbs attached. Do not overbake.
• Let cool completely in the pan on a wire rack before cutting into squares.